Promises
by Nameless Fenrir
Summary: Almost half a year has passed, since the demon world tournament and Yusuke was just about to adapt to his old life until someone he thought dead comes for a visit. I suck at summaries, so just read and find out who it is!
1. PrologueTeaser

**Authors Note: My first attempt on a** Yu Yu **Hakusho Fanfic, please enjoy reading and feel free to review!**

"What, ya stupid or what? How come, that you suck at just some easy exercises like thas?" The bold redhead laughed and almost caught a nice uppercut from the just slightly older boy, next to him.

"Geez...it gives me a head-crack just starin' at it..."

"You'd better give your best and pass the qualifying exams!" Kuwabara laughed and reached into his desk's drawer to pull out some snacks he hoarded there.

"heh, all Keiko's fault to force me into that stupid college!" Yusuke leaned back in his seat and stared out of the window. A storm was about to break out and dark clouds marred the sky today. It was almost half a year now, since he entered the tournament of the demon realm, fighting to get a hold on the throne. Well...he was too early like Raizen said and he wasn't unsatisfied with what he was able to achieve in such a short time.

"What're you thinking? You keep staring at those clouds, better stick your eyes on those books, before Keiko comes nagging at me!"

Ever since Kazuma made it into that college, he became quite good at learning, much to his older sisters relief and so, he spent most of his time either beeing at home and keeping his nose in his books, or beeing together with his friends, whenever he had some spare time. Life was going on in an almost constant, peaceful everyday habit and he was starting to get bored.

It wasn't bad, like it was now, though. With Enki ruling over Makai, there were rarely any interferences with Yokai anymore. Everything would be quiet and nice, at least for the next three years, until the Demon Realm Tournament was held again.

He shook his head and smiled. "Uhm...nothing. Everything is just fine!"

Rain poured down on the streets and people were in a haste to find a dry place to stay, as he left Kuwabara's house, leaving the door open for some moments, so a thoroughly soaked Eikitchi could storm into it, mewling and complaining. He smiled as Kazu-san instantly wrapped it into a towel as the door fell shut. Thunder roared across the sky and the lightning made the horizon flicker in a bright flash of light. He didn't care about getting wet, as he walked back home. That was until he could sense the yoki coming from a tree nearby.

"Yo, long time no see, Hiei! What brings you here?" He greeted the shorter yokai and grinned, lifting his head up, to look at him. After the tournament, everyone said goodbye and left, promising to see each other again at the next tournament. He did not expect to see Hiei first, of all people he left behind in Makai.

The three eyed demon, landed just some steps before him, his look as serious as ever and his piercing eyes darted on him.

"I am here to carry out a message. Hokushin wishes to see you, so don't keep him waiting for too long." He stared at Hiei for a moment, eyes widened and trying hard to think of a reason.

"See me? Well..." Yusuke just nodded, as the other male passed him, not even bothering to answer, or look back.

\- "Where're you going?"

"See someone and then leave this world again..." And with that, he just disappeared.

So, the old servants of his demon ancestor wanted to see him. Must be something important, to even mobilize someone like Hiei, to find him. While he was thinking, he automatically headed for the direction, where his house was. His mother ought to be away and Keiko was still in school he knew, so maybe it was a good idea to inform Kurama if Hiei would not, or hasn't already. He took off his shoes and stepped inside the house as something felt strange.

He was aware of a presence, but could not pinpoint what, or where it was, as his eyes tried to search for anything, that was out of place. The house was quiet, almost eerily quiet and strangely empty, but somehow, he felt like having a deja vu. If only he could find out...

"Yo, son..." Yusuke almost fell over as he practically jumped the moment, he was hearing that voice.

"What the f...whoa, don't you sneak up on me like that ya old bastard!" How? He stared into the face of his ancestor and his breath almost hitched, while the demon lord burst out laughing, his deep voice rumbling from his chest, as he leaned against the kitchens doorframe and watched the black-haired youth with amusement.

"Why are you here and how in hell could you possibly be alive?" This was not a dream and he didn't remember passing out, or beeing hit by a car a second time...

"Hm...well, a long story so you'd better get your ass seated and listen."

He was too surprised to even complain and somehow, the half-yokai had the feeling, that it will be a quite complicated kind of story, his "dad" was about to tell...


	2. Chapter 1

**About six months ago...**

 _Enki-sama!" One of the guards almost came rushing into the throne room, the red Oni had taken for himself, the man looked as if he just ran the whole way from the first, to the highest floor. Huge stacks of papers towered on his desk and even began to spread out onto the floor._

 _"Huh? What is it? I...am so busy right now, is it urgent?" Just one week has passed, since he won the Demon Realm Tournament and already the correspondence between his new appointment and the rest of Makai grew until his bureau was full of paper and then there was also the correspondence between Makai and the Spirit Realm...well...being the king of a whole world was hard work and no one said, it was easy._

 _Koko, the blonde yokai and more or less his queen now, threw a pondering glance at the guard and sighed. "Well darling, if he had to come in here, it must be of some sort of importance. Anyway, we could need a break!" She reached for her sake bottle and took a long gulp of it, while her husband leaned back, almost reluctantly to do so._

 _"Okay then, what's up?"_

 _"I didn't mean to disturb you, Enki-sama, but, there's a group of men, who want to talk to you about the tournament!"_

 _Both, Enki and Koko frowned._

 _"Did they mention the reason?"_

 _-"Uhm...Yes my Lord and they also said, that you should come to the tournament grounds!"_

* * *

Most of the time, Yusuke just listened to his ancestors words, occasionally nodding in agreement, or in sympathy, while Raizen explained.

"So, the dark tournaments committee paid Enki a visit just to tell him, that he was allowed to make a wish and that's why you're resurrected?"

Raizen nodded and took a small sip from his tea. At least, the boy knew how to make one, he thought almost amused, as his purple eyes once again seemed to focus on something distant.

"Well, Enki is a good man, sometimes too soft, but definitely one with the right heart and ambition, to rule makai through peace. He was surprised at first and then, he met up with the rest of my old comrades to sort things out and the decision made afterward seemed to be the best option, they could come up with together."

Again, Yusuke nodded, his gaze fixated on the ashen-haired yokai. So, he didn't make this wish alone. The day Raizen died, was the first time he saw his father's old sparring partners and he came to realize, what kind of man the Toshin was. One who would not be forgotten by those who considered him not just a worthy opponent, but also a friend. Despite the centuries that passed, since they saw each other and despite his sudden vow to never eat a human again. No...it was no wonder, they missed him and he understood, why they wanted him back. Or so he thought.

"So, in the end, they really missed you, eh?" A true smile from the younger yokai but Raizen shook his head.

"No, son not just because of sentiments and nostalgia. There was another reason and if I was asked, I might have objected..."

He sighed and looked at his teacup.

"As you know, there will be a second tournament again in three years time. Already, there's a lot of stirring in the demon world and no one can predict, who will win next time."

"Is it because of the other two, why they resurrected you?"

He shook his head.

"No. Mokuro has given up her throne as a ruler and she does not wish to do so again. And about Yomi. Well...people can change and it seems, that you really touched something inside that baka's head. Nobody, even I can't tell, what he's up to next time we see him again. But...I don't think that he still clings to his plan to conquer. However, we do not know who might win next time and not just my comrades, but also Mokuro and Enma Sr. agreed that it could possibly be an unknown, aggressive yokai claiming the throne and wage war against Ningenkai and the spirit realm. And that's where I entered the plan..."

"Okay, I got it. They want you to rule. Well, sounds not too bad, hm?"

From what he knew of Raizen and from what his friends told him about the battle god, Yusuke was more than confident, that at least his "father" was no bad choice at all. At least, he wasn't cruel, or war-crazed like some other yokai, he encountered during his time as a spirit detective and Raizen's heir. Plus he was considered one, if not the strongest yokai ever to be alive and that was a good reason not to cross with him.

But for some reason, Raizen seemed to hesitate.

"Say, why does it look like you're not that satisfied with their plan?"

"I do have a reason..." It was not like Raizen, to falter, but Yusuke could see in the way he looked at the window, that it must've something to do with the human realm.

"And that reason is?"

"She is here..."

"Who?"

The demon lord smiled. Not like those grins he usually gave his son, or those random smiles, while talking with Yusuke, or beeing amused. But a rare, almost loving one, that seemed to even soften the features of his predator-like face.

"The woman I once loved. As I died, I saw her...she's been reborn and she is here..."

So that must be the reason, why Hokushin wanted to see him. Maybe, he wanted him to help his ancestor to find her?

"And where is she? Look Tokyo sure is a huge city and there are millions of people here."

"Ya...I don't know her name, or where she is. That's why I came here. I have to find her, no matter how long it takes...but this time, I will not be stopped by anything or anyone!"

Okay, now that could be tricky. If Raizen was here and desperately searching for the woman he once loved, it meant that he might not be interested in joining the next tournament...until they found her of course. And that meant, that though he was alive, he would not claim the throne and...

"So, you decline the throne, until she's found? Mokuro was right, you really are a fool!"

Raizen chuckled and the wide grin spread across his face again.

"I never said that I was immune to doing something foolish. But yes, that's what I told them and I hoped, that at least you would understand me."

Why did he have to be so stubborn? But then again, they both were and he knew, how patient and persistent his ancestor could be. He waited for almost seven hundred years and he might do it again...

"I got your point and...I will help you. But only under one condition!"

The Toshin cocked his head in an asking manner.

"So?"

"Don't you dare try to starve yourself again! Eat! There's a lot of human scum outside!"

He laughed and shook his head.

"No! I made a promise once and it will not be broken, no matter what! Not until I see her again!"

"Tch! Stubborn idiot! But don't you dare try to bite me again, or my mom!"

"Oh, don't worry, this time, I can wait. And besides, this, I should give you. A letter from Hokushin, dunno what it's all about!" He reached into his belt and pulled out a sealed letter holding it out so Yusuke could grab it. He snatched it from Raizen's hand and broke the seal. Yes, that was the bald demons writing. He really had a rather girlish handwriting. Yusuke reminded himself to pick on that when he saw him next time. The letter was extremely short and consisted of only a handful sentences:

 _"If you can't return to makai, do us all just one favor:_

 _Convince Raizen-sama to come back..."_

And some lines below:

 _"...please."_

He arched a brow. If it wasn't such an important and serious matter, he would've laughed...


	3. Chapter 3

**Author's Notes:** Thanks everyone for the reviews and reading my story. As some of you might know, or have already found out, english is not my native language. So if you can find some strange grammar, or spelling, please just let me know I really appreciate some constructive critics! Now read and enjoy!^^

* * *

"Eat something!"

-"No!"

"Just anything, you give me the creeps when you're hungry!"

-"I said no!"

"Look Pocky's ain't made of humans, just try it!

-"How many times do I have to tell you? It's of no use and won't make it any better for me, so stop it already, boy!"

Yusuke gave a frustrated growl, answered by a low chuckle from the yokai lounging on his bed, one elbow propped up and with the same, craving, predatory smile on his face like the first time they met. He'd spent the last hours to convince him to at least eat normal human food, but more than a cup of tea, or some water, he just declined and it was getting more and more on his nerves.

"You're stubborn, why can't you just switch to human food, until you decided to eat humans again?"

-"Heh, you really ain't the sharpest knife in the drawer. As I told you. I can eat as much as you want me to, it won't stop the hunger for human flesh and it would only make it harder to withstand my hunger."

He was about to say something when the door was opened and he heard his mother's voice.

"Yu-Chan, are you at home? I bought you some lunch!"

"..." She was in the living room already, just another step and she will be in his room.

"What'cha starin' at, stupid old man? Hide yourself!" But the demon lord didn't even bother to move as the door opened.

"Huh? Did you say something? I thought you'd have guests!" He stared blankly at her and then over his shoulder to his ancestor, but nothing seemed to irritate Atsuko. Raizen did not move or say anything. His solemn eyes resting over her ever so peaceful, while Atsuko wasn't even aware of her son's strange visitor. She put a bag with a bento on his desk and smiled.

"Are you learning right now? I didn't mean to disturb you, so don't forget your lunch, I'm out tonight!"

-"Uhm...you're out again?" That was convenient, he thought. Better grab his ancestral father and drop him somewhere safe, before things got out of hand. He didn't want to imagine what happened when his ma found out.

"Yeah I'm away tonight, anything bothering you?" Her voice changed dangerously as she frowned at her son.

"Ya...no, no, that's okay, have fun ma and uhm...don't bother coming back late, I might go out, too!"

"Aw, really? You're going on a date then?"

"Well...sort of!" He needed to find a place for Raizen to stay. Somewhere far away from his home, where no one could find him, or even bother going...

"See ya, Yu-Chan!"

The door fell shut again and left a quite puzzled Yusuke and a mildly amused Raizen, who chuckled softly.

"She can't see me, as long as I do not wish to be seen. Remember? Normal humans miss this ability!"

Yusuke nodded and in the next instant, he quickly reached out, determined to punch the old demon lord, but failed miserably, as Raizen disappeared, faster than his eyes could even react. Claws sharp as razors dug lightly into his shoulder and he felt the demons breathing next to his ear.

"You're still too slow, my son..." He whispered and again, there was this mocking chuckle, that made his skin crawl. The last time, Raizen did this, was the day he died and that was when he bit his so called son. Yusuke gulped.

"Don't you worry. This time, everything changed and going out sounds good to me. I was about to go, find her by myself, but you could help me!"

He tried to grab the demon, but again he vanished and in an instant, lay sprawled out on his bed again.

"Train harder, until you're able to even just scratch me and I might think about going into full training with you!"

"Heh, I'm gonna beat the shit out of you, but not here in my ma's house."

The demon king arched a brow, grinning at his son.

-"So, what are you gonna do?"

"Take you somewhere safe. I know the perfect place for you to stay and for me to train, train a lot that is!" He grabbed his jacket and smiled.

"Wow, I really hope for you that Ba-san won't mind!"

"Huh? Ba-san?"

-"Yeah, my former sensei and a good friend of mine and Koenma!"

 _Several hours later._

The old woman was enjoying her ginseng tea, taking a long drag from her cigarette, as she and the rest of the gang watched Yusuke slamming against the nearby wall for the sixth time in about an hour and still peeling himself from it to attack his ancestor again and again.

"I told you to get out of your diapers first and then come after me, stupid boy!" A punch but Raizen did not even flinch, as he caught the younger man's fist and squeezed.

"Oowww...just shut up ya old idiot and fight seriously!" And again, he greeted the wall face first.

"Stop it already, it's boring!" He stepped closer to his son and laughed. Yusuke wheezed and spit out some blood, still trying to get back on his feet. He shook himself off and growled as his reiki level suddenly climbed up with enormous speed and he pointed his finger at Raizen.

"And I told you to shut up!" The Rei Gun covered the whole area with bluish light, but amidst its blast, a green aura could be seen and Yusuke went flying again.

"Baka..." Genkai sighed.

"Oi Raizen-san, how long do you plan on doing this? You're wrecking my garden!" Genkai took a sip of her tea and stood up, walking past the doors of her Dojo, to look where Yusuke landed.

"Just long enough until my son finally understands the meaning of "beeing superior" and "total disadvantage" and until then, it doesn't hurt to knock some sense into his numbskull!

The demon king was enjoying himself too much, for Yusuke's taste. That old bastard was way too strong for him and he knew it, but damn, he was no weakling either! He charged the white haired demon once again, watching him avoiding his effortless attacks, as if it was some kind of dance for him, with what seemed like no labor at all.

"Take it seriously, damn you!" His fist began to glow reddish and dark marks began to surface on his skin, as the younger yokai started his attack. He growled menacingly, his eyes turning red and his yoki bursting into a trail of energy, as he leaped forward, landing a hard punch into Raizen's belly. He slithered a few steps, but caught himself, without stumbling. A coarse laugh, as he brushed his hair behind his shoulders

"Oh, now you sure get to carried away, boy! Time to put an end to this!"

"An end? You must've been kidding because this time I will definitely...yaaaa!"

He was about to babble forth, but that was the point where Raizen decided, that it was better when he just quit goofing around. His aura blazed up and just before his son could even come into reach for another punch, he blasted him away in a heavy exposure of his own yoki, showing his all to eager son, what true power meant.

"If you can still walk, come over here and try again. But your puny results will always be the same, so don't bother and stop bitching, you start to piss me off!" He walked away, behind him, a trail of mud and debris and somewhere near the woods, Yusuke began to get back on his feet, stumbling behind Raizen and growling under his breath, as he reluctantly planted himself on the floorboard of the dojo. The demon king was already there, sitting next to Genkai and watched him with amusement.

"Hehe, don't look at me like that, try again tomorrow, yes?" He reached out his hand to ruffle the boy's hair.

"Fuck you!" Yusuke turned his head quickly to not just avoid his hand but to bite him as well.

"Argh...vicious kid! But I like that!" A hearty laugh was heard, joined by Genkai and Kurama while Kuwabara was still skeptical about Yusuke's new family.

"Wow, it's like having to Yusuke's...just that one can really chew off my ass..." He whispered to the Youko, who could not repress a smile.

"So, you don't plan on returning to makai? Wouldn't it go against the law of the Spirit World as well as the new rules of Makai?" Kurama asked and refilled Genkais teacup while he poured some tea for Raizen as well.

"Heh, it's not like I even care. Enki made an exception for me, restricted in a months time and what the spirit world is going to do about me..." He grinned and stared at his beaten up son.

"If they even wet themselves thinking of fighting Yusuke, imagine, what they think of going against me?"

Kurama smiled.

"So what are you going to do now? Even with your powers, it will be hard to find someone, who might be nothing more than just a normal person. There are a lot of people out there and she might even not be in this country at all."

Yusuke nodded while tending to his wounds and hissing. His old man sure had some good tricks up his sleeve...

"That's what I told him earlier...you can't just run around, looking for her without even knowing how she looks like!"

"Uhm...well, I never considered these things!" He laughed rather carelessly and somehow, he now looked just like Yusuke as he put a hand on his head, trying to imagine his next moves. The rest watched the two Yokai and exchanged amused looks. Well, like father, like son...

"Heh, so that's where it comes from..." Genkai smirked, looking at Yusuke while Kurama chuckled.

"Well, it can't be helped, now that you're here, chances are high that maybe, some kind of coincidence might help us. Let's keep our eyes and senses opened." They nodded in silence until the old lady stood up and pushed der cigarette off.

"Stay here, as long as you want, I don't care either. And if you want to train your dimwitted offspring, do, as you like, it's about time for him to finally get stronger!"

"Tch...bet he can do much better! As long as I don't have anything better to do that is!"

None of the two knew, where this would take them, but Yusuke grinned almost devilishly and now, that Raizen was back, he was even more spurred to improve his abilities.

"I'll make you choke on your words, old man!"


End file.
